PCMS Task After Moderate-to-severe Stroke

Summary

Researchers at the University of Pittsburgh are conducting a research study to see how combining brain, nerve, and hand stimulation affect hand movement after stroke. The primary purpose of this study is to examine changes in the connection between the brain and the weak hand muscles after the combined brain, nerve, and hand stimulation. The primary hypothesis is that the combined brain, nerve, and hand stimulation will increase the the connection between the brain and the weak hand muscles. The secondary purpose of this study is to examine changes in weak hand's movement and function after the combined brain, nerve, and hand stimulation. The secondary hypothesis is that the combined brain, nerve, and hand stimulation will increase weak hand movement and function.

Conditions

• Stroke

Interventions

DEVICE

Task-specific PCMS

120 pairs of TMS and PNS volleys will be administered during electromyography-triggered functional electrical stimulation (FES)-assisted task-specific training (task-specific PCMS). In the task-specific PCMS, participants will first grasp a spherical ball when prompted by an auditory 'Ready' cue, and upon seeing a visual 'Go' cue will voluntarily extend the wrist and fingers to release the ball. After the 'Go cue', our customized stimulation delivery algorithm triggers the TMS and PNS only when the extensor digitorum communis (EDC) muscle activity exceeds a pre-determined threshold. The algorithm will then trigger FES to EDC after detecting EDC activity (\~2 ms after PNS) for the next 2 seconds, allowing the pairing of PCMS (TMS and PNS) with the voluntary movement of EDC without the confounding effects of FES.

DEVICE

Task-specific sham-PCMS

120 pairs of sham-PCMS stimuli will be administered during task-specific practice. The TMS coil will be placed \~10 cm behind the participant's head, and PNS electrodes will be placed in the same position as for task-specific PCMS, but no stimulation will be delivered. Like the task-specific PCMS condition, participants will perform the same grasp and release a ball task in an identical manner. FES will be delivered after detecting voluntary EDC activity, similar to the task-specific PCMS condition.

DEVICE

PCMS-rest

120 pairs of TMS and PNS volleys will be administered with the EDC muscle at rest every 10 s (\~20 min, 0.1 Hz). TMS will be used to elicit motor-evoked potentials (MEPs). Antidromic activation of spinal motor neurons will be elicited by supramaximal peripheral nerve stimulation (PNS) applied to the radial nerve near the elbow. Volleys will be timed to arrive in the spinal cord based on central and peripheral conduction times calculated for each subject so that the pre-synaptic terminal is depolarized via TMS \~1-2 ms before spinal motor neurons are depolarized via PNS at a pulse duration of 200us. We will also perform stimulation of the cervical roots (C-root) by placing the coil behind the neck and stimulating the C-root (C6 and C7 vertebrae), which innervate the finger extensor muscles. Conduction times will be calculated from latencies of the primary motor area (M1) MEP, C-root, and M-wave.

Sponsors & Collaborators

• Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

  collaborator NIH

• University of Utah

  lead OTHER

Principal Investigators

• Amit Sethi, PhD · University of Utah

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-03-29

Primary Completion

2025-12-21

Completion

2025-12-21

FDA Device

Yes

Countries

• United States

Study Locations